功能导向p-n型MoS2/SnO2异质分级结构的构筑及气敏-光催化性能

This project integrates the hierarchical model and heterjunction model to prepare double-function SnO2/MoS2 material.By means of crystal engineering, hierarchical SnO2 with exposed high activity crystal face was prepared. Then p-type MoS2 nanosheet with narrow band was loaded on SnO2 utilizing the energy-band engineering to prepare p-n type heterojunction composite. With the aid of coupling effect, synergistic effect and built-in electric field of p-n junction, the adsorption and response of guest molecules and the carrier behavior of SnO2 were regulated. Then double-function SnO2/MoS2 with excellent gas sensing performance and visible light catalytic activity was obtained. The synthesis law, micro-structural characteristic, interface behavior, charge transport and spectral response of this material were systematically studied, aiming at reveal the fundamental scientific problems including electronic structure, energy band structure, migration and conversion rules of photoproduced electrons and holes on the interface. Rules of detection and degradation for guest molecules in industrial waste gas and water of the obtained material were researched. The inherent correlations between structure and performance were illuminated. Mechanisms of gas sensing and photocatalysis were further cleared.This will enrich the research contents of the construction of novel gas sensors and catalytic systems.

本项目将分级结构模型与异质结模型融为一体，运用“晶体工程”合成暴露高活性晶面的SnO2分级结构，借助于“能带工程”可控负载p型窄带隙MoS2纳米片，构筑p-n异质结复合材料，借助于耦合效应、协同效应和p-n结内建电场调节SnO2对客体分子的吸附、响应及载流子行为，制备具有高效气敏响应及可见光催化活性的“双功能”MoS2/SnO2异质结材料。系统研究该类材料的合成规律、微结构特征、界面行为、电荷输运和光谱响应性，揭示异质界面的电子结构、能带结构、光生电子空穴的界面迁移转换规律等基本科学问题；探究分级异质材料对工业废气、废水中客体分子的检测及降解规律，阐明材料结构与性能之间的内在关联，明晰气敏响应机制与光催化机制，丰富构建新型高效气敏、光催化体系的研究内容。

半导体材料在气敏领域和光催化领域都占有重要的地位，在环境污染日益严重的今天，发展具有多功能特性的半导体材料具有巨大的研究意义。本项目将分级结构模型与异质结模型融为一体，合成了具有分级结构的异质结纳米材料。该项目首先构筑了分级SnO2结构，然后通过非均匀形核可控负载p型窄带隙MoS2纳米片，成功构筑了p-n异质结复合材料，借助于异质结的耦合效应、协同效应和p-n结内建电场调节主体材料对客体分子的吸附、响应及载流子行为，制备出具有高效气敏响应及催化活性的“双功能”MoS2/SnO2异质结材料。项目实施过程中系统研究了SnO2及MoS2材料的合成规律、微结构特征、能带结构、光生电子空穴的界面迁移对催化、气敏性能的影响规律；阐明了材料结构与性能之间的内在关联，明晰了气敏响应机制与光催化机制，构建了新型高效的气敏材料及光催化/催化材料。